For the fourth year in a row, the Innocence Project, an organization dedicated to overturning wrongful convictions as well as making substantive reforms to the criminal-justice system, has released an annual report of people who were exonerated this year after spending time behind bars for crimes they did not commit.

This year's roundup includes 22 people -- 13 of whom are black -- who, combined, served more than 279 years because of problems like eyewitness misidentification, faulty forensics and false confessions before they were freed. The Innocence Project says that nearly half of its cases involved innocence proved by new developments in DNA technology.

Just a few examples:

Faulty hair analysis contributed to the wrongful conviction of Willie Grimes in North Carolina who served 24 years for a rape he didn't commit. In response to exonerations in two other cases where FBI analysts provided faulty hair analysis, the FBI announced that it would undertake a widespread review of cases involving hair analysis ...

David Lee Gavitt, who served more than 25 years in Michigan prisons for the arson murder of his wife and two daughters, was exonerated after prosecutors agreed to vacate his conviction because it was based on outdated arson science ...

Drayton Witt served a decade in prison for shaking to death a five-month old boy before prosecutors acknowledged that the opinion of the medical examiner was incorrect ...

While justice and a return to freedom for the wrongfully convicted is something to celebrate, President of the Innocence Network and Co-Director of the Wisconsin Innocence Project Keith Findley delivered a somber message in his letter accompanying the report. "[R]emember that in many ways, those profiled are the lucky ones," he said. "For every person who walked out of prison a free individual this year, there are many more still incarcerated, hoping that 2013 will be the year they finally get the break that will prove their innocence."